1. Field of the Invention
Apparatuses consistent with the present invention relate to an antenna having an extended operation frequency bandwidth. More particularly, the present invention relates to an antenna having an extended operation frequency bandwidth, which enables transmission and reception of RFID signals and radio signals via a single antenna.
2. Description of the Related Art
Recently, ubiquitous sensor network (USN) is attracting attention as a basic infrastructure for realizing a ubiquitous society which is becoming extremely important in the area of information technology.
The USN is a technique that attaches a communicable tag to all objects: detects environment information based on recognition information of the objects, which is acquired from using the tags; and manages and utilizes this detected information over networks. The core of the USN is a radio frequency identification (RFID) system. The RFID system includes: a reader, an antenna, a tag, a server, and a network. The reader is responsible for reading and storing information to and from the tag. The antenna is responsible for exchanging the data stored from the tag in a certain frequency according to a certain protocol.
Convergence of the RFID system and mobile communication produces a new technique and service called a mobile RFID (mRFID). The mRFID includes: a tag, a reader, an antenna, and a processing module mounted to the mobile communication terminal. This mRFID technique provides useful information services to a user by reading out information from other tags, or forwarding information from the mobile communication terminal to another device using the tag of the mobile communication terminal.
Meanwhile, an RFID antenna adapted to the mRFID technique transmits and receives radio signals in the band of 908.5˜914 MHz, whereas a communication antenna dedicated to the mobile communication terminal transmits and receives radio signals in the band of 824˜896 MHz. There is a small difference between the bands for the RFID radio signals and the mobile communication radio signals. However, since a mobile communication antenna of a conventional mobile communication terminal uses the narrowband, it is difficult to effectively transmit and receive even the RFID radio signals. Hence, the conventional mobile communication terminal separately employs and uses the RFID antenna and the mobile communication antenna in order to implement the mRFID technique.
As such, when the RFID antenna and the mobile communication antenna are provided separately, the increased size of the mobile communication terminal is inevitable. This size increase is contrary to the technological advancements in mobile communication terminals for making mobile communication terminals smaller through miniaturization and integration of the mobile communication antenna.
Therefore, it is possible to avoid the size increase of the mobile communication terminal, due to the plurality of antennas having to be mounted, by transmitting and receiving both the RFID radio signals and the mobile communication radio signals via a single antenna.